Method of laminating



Jan. 30, 1940. I J. F. McWHORTER ET AL 2,188,721

METHOD OF LAMINATING Filed July 19, 1935 2 Sheets-Sheet 1 INVENTORSx/bH/V If 1% Man rev? ATTORNEYS Jan. 30, 1940. J. F. M WHORTER ET AL2,188,721

METHOD OF LAMINA'I'INQ Filed July 19, 1955 2 Sheets-Sheet 2 INVENTORSJon/v F 1% Mann? ph'nkvsr D. G'EYEI? Patented Jan. 30, 1940 z,1ss,7 21

PATENT OFFICE METHOD OF LAMINATIN G John F. McWhorter and Harvey D.Gcyer,

Dayton, Ohio, assignors to General Motors Corporation, Detroit, Mich., acorporation ofDela- Application July .19, 1935, serial No. 32,174

4 Claims.

This invention. relates to packing gaskets such as automobile enginehead gaskets, and a method of making same.

An object of this invention is to provide an improvedform of gaskethaving a reinforcing metal sheet, preferably steel, and sheets ofasbestos fiber or other non-metallic fibrous material strongly .surfacebonded to the reinforcing sheet by a relatively thin stratum ofrelatively low meltlng metal. I

'4 Another object of the invention is to provide a simple economical andhighly efficient method olf1 bonding such fibrous sheets to thereinforcing s eet.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to'theaccompanyingdrawings wherein a preferred embodiment of the-presentinvention is clearly shownw In the drawings:

Fig. 1 is a face view'of anautomobile engine head gasket made accordingto this invention.

Fig. 2 is a section on line 2-2 of Fig. 1.

Figs. 3, 4 and 5 illustrate steps in the method 26 of making thegaskets.

Fig; 3 illustrates the spray-coating of an asbestos fiber sheet with athin coating of relatively low-melting metal.

Fig. 4 is an end view of the apparatus of Fig. 3.

Fig.- 5 illustrates the further steps of the method, namely, the dipcoating of the reinforcing steel sheet with a relatively low-meltingmetal and the bonding of two separate spray-coatedflber sheets to thecoated steel sheet shortly after it emerges from the dip-coating metaland while said dip-coating metal is still in fluidor plastic condition.The method illustrated in continuous.

Simliar reference characters refer to similar parts throughout theseveral views.

The automobile engine head gasket shown in Figs. 1 and 2 comprises acentral reinforcing metal sheet l0, preferably steel, and two asbestosilbersheets ll very strongly bonded to the steel 4 sheet by relativelythin strata l2 of a suitable relatively low-melting metal such as tin,zinc, lead, copper, bismuth, cadmium or any suitable low-melting alloyor alloys of such'metals. The bonding strata l2 are keyed or interlockedinto the fiber interstices of the fibrous sheets ll whereby said fibroussheets are flrmlyheld in place over the entire contacting surface withthe metal sheet l0 and hence can be pulled loose therefrom only bytearing off the unbonded layers of the fibrous sheets, that is to say,the bond is stronger than the fiber sheet l l itself: For engine :headgaskets, or any gaskets which must withstand similarly hightemperatures, the fiber sheets I l preferably are of asbestos fabric andthe low-melting metal strata l2 are chosen of such 5 metal or alloy thatit can properly withstand the high temperatures experienced in usethereby without melting. a

-In the method of this invention a long unperforated blank is first madecomprising a central steel sheet with the two asbestos sheets bondedthereto by the bonding strata l2. s'I'he desired design of engine headgasket or any other design of gasket is then simply punched or cut outof this long blank by suitable dies. In making the blank, one surface ofeach of twoasbestos sheets is spray-coated with molten metal to providea strongly adhering relatively thin coat of lowmelting metal thereon.Both sides of the'central steel sheet i0 is properly coated with alow-melting metal or alloy which will readily bond to the spray coat ata convenient temperature. For this purpose it has been found practicalto suitably flux the steel sheetand then dip it into a molten alloycomprising 20 parts copper, 40 parts lead, and 40 parts tin, which coatsthe steel sheet in on both sides thereof in a simple and eflicientmanner.

This coated steel sheet is then run through a pair or a series of pairsof pressure rolls with the two spray-coated asbestos sheets pressedagainst its opposite sides while the dip coating on the steel sheet isyet in fluid or plastic condition, that is, before it has cooled offsumciently to become solid. The pressure of the rolls causes the spraycoats on the two asbestos sheets to solder or alloy with the'dip coat onthe steel sheet and thus very strongly bond the asbestos sheets to thesteel sheet throughout theirentire contacting surfaces. This method isillustrated in Figs. 3, 4 and'5.-

Figs. 3 and 4 illustrate an apparatus by which the asbestos sheets maybe suitably spray coated. This apparatus comprises a container," inwhich a supply of the above described low-melting metal ii is kept in amolten state by the gas burner 22 located under the container 20.Directly above container 20 is mounted a rotating shaft 23 having aseries of thin metal spraying disks 24 fixed thereto, these disks 24being of a metal having a melting point sufflciently high to preventdamage thereto by insertion into the molten metal 2l. The level of themolten metal 2i is maintained so that only the lower portions of disks24 are immersed therein. Now when shaft 23 is driven at a suitably highspeed bythe motor 25 and the drive belt 25, the thin spray disks 24 willpick up the molten metal and throw it off radially in fine particles andat high speed.

. The higher the .speed of rotation of disks 24, the

smaller will be the size of the metal particles thrown off thereby, andvice versa within limits.

high speed against the fibrous sheet 21 that they partially penetrateinto the interstices between the fibers thereof while said particles areyet in molten or plastic state and thus-the spray coat is substantiallykeyed to the fibrous sheet 21 upon the immediate solidification bycooling of these metal particles. If the sheet 21 be of some vegetablefiber the molten particles should be quite fine and be of a suitablelow-melting al- 10y which will not burn the vegetable fiber to anymaterial extent before cooling off. If the sheet 21 be of asbestosfibrous material a higher melting metal or alloy may be used and also adeeper penetration into the sheet without any harmful results to thefibrous sheet. As stated above, the size of the metal particles may bereadily adjusted by adjusting the rotary speed ous length of theuncoated fibrous sheet 21 is unwound from reel 29, passes through thespray chamber 3|, and the spray-coated sheet is wound up on reel 30.after it emerges from the spray chamber. This spraying operation ispreferably continuous until theentire roll of fibrous sheet isspray-coated, and the roll may be of any convenient size orlength. Theportion of the fibrous sheet 21 within chamber 3| may be suitablysupported upon the rollers 33 which maintain the sheet 21 at a uniformdistance from the spraying disks 24. It is preferable to spray the metalparticles through an atmosphere of non-oxidizing or reducing gas inorder to prevent partial oxidation of the fine particles during transitor after they have been deposited upon the fibrous sheet 21. For thispurpose the chamber 3| is preferably kept filled with a suitablereducing atmosphere all during the spraying operation.

The subsequent steps in the method of this invention are illustratedsomewhat diagrammatically in Fig. 5. 40 designates a roll of uncoatedsheet steel on both sides of which are to be bonded the spray-coatedasbestos sheets from the two rolls 4| and 42, these asbestos sheetshaving been first spray-coated in the apparatus shown in Fig. 3 as abovedescribed. 43 is a flux tank containing a suitable flux 44 into whichthe steel. sheet 45 is led as it proceeds from the roll 40. 46 is astationary guide which may be used to keep the steel strip 45 submergedin the flux 44 so that both sides of the steel strip will be thoroughlycoated with the flux. 41 is a container for the molten low-melting alloy48 with which the steel sheet 45 is dip-coated. This alloy 48 is meltedand maintained in the desired molten condition by a suitable gas furnace49 thereunder. 50 is one form of. a suitable sta: tionary guide whichmay be provided to keep the steel strip 45 fully submerged in the moltenalloy 48 as it passes therethrough. Suitable lateral guides (not shown)for the steel strip 45 may also be used. As the steel strip emerges fromthe molten alloy 48 at 5| it is completely coated with an adhering stillmolten film of this alloy. From this point it passes through the chamber52 which is maintained at such a temperature that by the time thedip-coated steel sheet reaches the pressure rollers the alloy coatingthereupon is still in a fiuid or preferably semi-. fluid state. In thiscondition the steel strip together with the two spray-coated asbestosstrips 53, from rolls 4| and 42 respectively, passes between thepressure rollers 60 with the spray coats 28 on the asbestos strips inpressure contact with the dip coats on the steel strip. These rollers6|! are so adjusted as to apply sufflcient pressure to cause thespray.coats to strongly bond to the dip coat on the steel strip by a solderingor alloying action, since by the time the assembled strips have passedthrough the last set of pressure rollers 60 the alloy has becomesufiiciently cooled to become solid and firmly hold the asbestos stripsto the steel strip. Fig. 5 shows three pairs of pressure rollers 60, allof which are geared together by suitable intermediate gears and drivenby the electric motor 5| through a gear reduction unit 62 and the chainor belt drive 63. A different pressure adjustment for each pair ofrollers 60 may be had if desired, the first pair of rollers 6|)preferably serving primarily as guide rollers for aligning and smoothingout the three strips to be bonded together. If desired only a singlepair of pressure rollers may be used. The completely bonded strips orintegral strip 65 passes from the last pair of rollers 60 and is shownin Fig. 5

as being rolled up on the storage drum 66. Strip 65 may if desired bepassed directly to a shearing machine and cut up into suitable lengthsand stored in flat form rather than be rolled up on a drum. The abovedescribed operation shown in Fig. 5 is preferably continuous until theentire length of steel strip on roll 40, which may be of any convenientsize, is used up. The integral strip 55 forgns the blank from which thedesired design of g skets may be rapidly punched out by suitable dies,If desired the punched out gasket may be coated with a graphite bearingsolution of pyroxylin or may be given such other known treatment as isdesired prior to use as an engine head or other gasket. Gaskets madeaccording to this invention are suitable for sealing intake and exhaustmanifolds on automobile engines and the like, or joints in pipe linesused to convey water, gas, steam or other .gases and liquids at highpressure, or any other desired application.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. The steps in the method of making a laminated sheet consisting of anon-metallic fibrous lining bonded to a metal sheet, comprising:providing a relatively thin spray coat of a low-melting metal upon saidfibrous lining by throwing fine particles of molten low-melting metalwith high speed against said fibrous lining and thereby causing a keyedadherence thereto, further coating said metal sheet with a metal whichwill readily bond to the metal forming said spray coat, then pressingthe' spray-coated surface of the fibrouslining against the coatedsurface of said metal sheet while the coating on the metal sheet is in afluid or semi-fluid state and thereby surface-bonding said spray coat tothe metal coat upon said metal sheet. 2. The steps in the method ofmaking a laminated sheet consisting of a non-metallic fibrous liningbonded to a metal sheet, comprising: providing a relatively thin spraycoat of a low-melting metal upon said fibrous lining by throwing fineparticles of molten low-melting metal with 7 high speed against saidfibrous lining and thereby causing a keyed adherence thereto, dipcoating said metal sheet with a molten metal which will readily bond tothe metal forming said spray coat, then progressively passing said metal'sheet and fibrous lining between pressure rolls with force with suchhigh speed against said fibrous sheets as to cause particles of themetal coating to embed themselves into the fibrous sheets to asubstantial depth, further coating 'both sides of said metal sheet witha metal which will readily bond to the metal coatings on said fibroussheets, then pressing themetal-coz'tted surfaces of the two fibroussheets against the metalcoated surfaces of said metal sheet at atemperature which will strongly bond the contacting metal coatstogether.-

4. The steps in the method of making a long continuous strip oflaminated material, comprising: metal-coating one face of each of twolong continuous strips of fibrous material'by throwing fine' particlesof molten low-melting metal thereupon by means of centrifugal force withsuch high speed as to cause particles of said metal to embed themselvesinto the fibrous ma- .terial to a substantial depth, further coatingboth 2 sides of a long continuous metal strip with a metal which willreadily bond to the metal coatings on said fibrous strips, and thenwhile the coatings on said metal strip are in a fluid or semi-fluidstate progressively passing said metal 26

